During the 1980s, there was a great increase in the number and use of personal computers and workstations interconnected by LANs which allowed local users to share resources. However LAN growth has been unpredictable and provincial. Consequently the need to develop Wide Area Networks (WANs) to internetwork LANs, high performance terminals and work stations in an effort to organize, manage and provide rapid access to distributed information resources has grown in importance during the 1990s. WANs provide a bridge between the PC/LAN environment and the large host environment giving PC users access to remote high bandwidth applications such as imaging, CAD/CAM and data base management. A barrier to the development of WANs has been the inability of telecommunications facilities to meet high bandwidth availability and reliability requirements of new computer applications which manipulate ever increasing amounts of information.
Others in the past have attempted to combine several narrow band channels to form a wideband facility employing the public switched digital network. These arrangements typically establish each narrow band channel independently of one another resulting in multiple transmission paths routed through different network equipment. Thus each narrow channel may have a different length and propagation time or transmission delay. An arrangement embodying this approach is detailed in U.S. Pat. No. 4,577,312 issued on Mar. 18, 1986 to Nash. The system shown in this prior patent breaks a high bandwidth information stream into multiple streams then transmits information simultaneously over multiple narrow band channels reconstructing the original information stream at the receiving end. An associated phone set is used to establish each connection independently of preceding paths. Transmission delay on each connection is measured by sending and receiving a test pattern. A compensating delay is then inserted into each line so that information sent along each narrow band channel arrives at a constant delay across all channels. This arrangement proves troublesome because any central office in any of the multiple paths established may, at any time, generate a frame slip (extra bit) in an attempt to maintain line synchronization. When a frame slip is generated, all delays previously determined become invalid thereby degrading network performance. New delay parameters must be ascertained and the multiple channels re-synchronized. Resynchronization of the multiple channels is difficult because of the unpredictable manner in which the frame slips are generated in an extensive network. The present invention is directed toward eliminating the above deficiencies of prior art systems.